scholarly journals Flexibility analysis and design of heat exchanger network for syngas-to-methanol process

2021 ◽  
Author(s):  
Jinchang Liu ◽  
Pingping Zhang ◽  
Qiang Xie ◽  
Dingcheng Liang ◽  
Lei Bai
Keyword(s):  
Energy Consumption ◽  
Heat Exchanger ◽  
Operating Conditions ◽  
Stable Operation ◽  
Heat Exchanger Network ◽  
Total Cost ◽  
Analysis And Design ◽  
Flexibility Analysis ◽  
Stable Operating ◽  
Pinch Technology

AbstractThe heat exchanger network (HEN) in a syngas-to-methanol process was designed and optimized based on pinch technology under stable operating conditions to balance the energy consumption and economic gain. In actual industrial processes, fluctuations in production inevitably affect the stable operation of HENs. A flexibility analysis of the HEN was carried out to minimize such disturbances using the downstream paths method. The results show that two-third of the downstream paths cannot meet flexibility requirements, indicating that the HEN does not have enough flexibility to accommodate the disturbances in actual production. A flexible HEN was then designed with the method of dividing and subsequent merging of streams, which led to 13.89% and 20.82% reductions in energy consumption and total cost, respectively. Owing to the sufficient area margin and additional alternative heat exchangers, the flexible HEN was able to resist interference and maintain production stability and safety, with the total cost increasing by just 4.08%.

scholarly journals Flexibility Analysis and Design of Heat Exchanger Network for Syngas-to-methanol Process

2020 ◽  
Author(s):  
Jinchang Liu ◽  
Pingping Zhang ◽  
Qiang Xie ◽  
Dingcheng Liang ◽  
Lei Bai
Keyword(s):  
Energy Consumption ◽  
Heat Exchanger ◽  
Stable Operation ◽  
Economic Gain ◽  
Heat Exchanger Network ◽  
Total Cost ◽  
Analysis And Design ◽  
Flexibility Analysis ◽  
Operation Conditions ◽  
Pinch Technology

Abstract The heat exchanger network (HEN) of syngas-to-methanol process was designed and optimized based on pinch technology under the stable operation conditions to balance the energy consumption and economic gain. Inevitably, the fluctuations of production affect the stable operation of HEN in real industrial processes. The flexibility analysis of HEN was carried out in this study to minimize such disturbances by using the downstream paths method. The results show that 2/3 downstream paths cannot meet flexibility requirements, indicating that HEN doesn’t have enough flexibility to accommodate the disturbances in the actual production. The flexible HEN was then designed with the methods of dividing and subsequent merging, which led to 13.89% and 20.82% reduction in energy consumption and total cost, respectively. Thanks to enough area margin and additional alternative heat exchangers, the flexible HEN is found to be able to resist interferences and maintain the production stability and safety, only sacrificing the increase of total cost increase by 4.08%.

scholarly journals Heat Exchanger Network Retrofit of an Oleochemical Plant through a Cost and Energy Efficiency Approach

2021 ◽  
Vol 5 (2) ◽  
pp. 17
Author(s):  
Valli Trisha ◽  
Kai Seng Koh ◽  
Lik Yin Ng ◽  
Vui Soon Chok
Keyword(s):  
Energy Consumption ◽  
Heat Exchanger ◽  
Cost Effective ◽  
Capital Cost ◽  
Global Market ◽  
Annual Saving ◽  
Heat Exchanger Network ◽  
First Case ◽  
Payback Time ◽  
Better Than

Limited research of heat integration has been conducted in the oleochemical field. This paper attempts to evaluate the performance of an existing heat exchanger network (HEN) of an oleochemical plant at 600 tonnes per day (TPD) in Malaysia, in which the emphases are placed on the annual saving and reduction in energy consumption. Using commercial HEN numerical software, ASPEN Energy Analyzer v10.0, it was found that the performance of the current HEN in place is excellent, saving over 80% in annual costs and reducing energy consumption by 1,882,711 gigajoule per year (GJ/year). Further analysis of the performance of the HEN was performed to identify the potential optimisation of untapped heating/cooling process streams. Two cases, which are the most cost-effective and energy efficient, were proposed with positive results. However, the second case performed better than the first case, at a lower payback time (0.83 year) and higher annual savings (0.20 million USD/year) with the addition of one heat exchanger at a capital cost of USD 134,620. The first case had a higher payback time (4.64 years), a lower annual saving (0.05 million USD/year) and three additional heaters at a capital cost of USD 193,480. This research has provided a new insight into the oleochemical industry in which retrofitting the HEN can further reduce energy consumption, which in return will reduce the overall production cost of oleochemical commodities. This is particularly crucial in making the product more competitive in its pricing in the global market.

scholarly journals Experimental Study for Counter to Cross Flow Air-cooled Heat Exchangerof Annular Tube having Internal Circular grooving at Different pitches - A Review

2020 ◽  
pp. 268-274
Author(s):  
Suneel Nagar ◽  
Ajay Singh ◽  
Deepak Patel
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Cross Flow ◽  
Operating Conditions ◽  
Theory And Practice ◽  
Thermal Flow ◽  
Total Cost ◽  
Literature Theory ◽  
Modern Analytical ◽  
Annular Tube

The objective of this study is to provide modern analytical and empirical tools for evaluation of the thermal-flow performance or design of air-cooled heat exchangers (ACHE) and cooling towers. This review consist various factors which effect the performance of ACHE. We introduced systematically to the literature, theory, and practice relevant to the performance evaluation and design of industrial cooling. Its provide better understanding of the performance characteristics of a heat exchanger, effectiveness can be improved in different operating conditions .The total cost of cycle can be reduced by increasing the effectiveness of heat exchanger.

A Practical Approach to Energy Optimization Using Pinch Analysis: A Case Study of an Oil Refinery

2021 ◽  
Author(s):  
Paschal Uzoma Ndunagu ◽  
Emeka Emmanuel Alaike ◽  
Theophile Megueptchie
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Energy Savings ◽  
Operating Cost ◽  
Energy Optimization ◽  
Distillation Unit ◽  
Pinch Analysis ◽  
Cost Index ◽  
Heat Exchanger Network ◽  
Total Cost

Abstract The objective of this paper is to perform an energy optimization study using pinch analysis on the Heat Exchanger Network (HEN) of a Crude Distillation Unit to maximum heat recovery, minimize energy consumption and increase refining margin. The heat exchanger network (HEN) considered comprises exchangers from the pre-heat section of the atmospheric distillation unit, which recovers heat from the product streams to incrementally heat the crude oil feed stream before entering the furnace. This paper illustrates how to perform a detailed HEN retrofitting study using an established design method known as Pinch Analysis to reduce the operating cost by increasing energy savings of the HEN of an existing complex refinery of moderate capacity. Analysis and optimization were carried out on the HEN of the CDU consist a total of 19 heat exchangers which include: process to process (P2P) heat exchangers, heaters and coolers. In the analysis, different feasible retrofit scenarios were generated using the pinch analysis approach. The retrofit designs included the addition of new heat exchangers, rearrangement of heat exchanger (re-sequencing) and re-piping of existing exchangers. Aspen Hysys V9 was used to simulate the CDU and Aspen Energy Analyser was used to perform pinch analysis on the HEN of the pre-heat train. Several retrofit scenarios were generated, the optimum retrofit solution was a trade-off between the capital cost of increasing heat exchanger surface area, payback time, energy / operating cost savings of hot and cold utilities. Results indicated that by rearrangement (Re-sequencing), the pre-heat train can reduce hot (fired heat) and cold (air and cooling water) utilities consumption to improve energy savings by 8% which includes savings on fired heat of about 4.6 MW for a payback period of 2 years on capital investment. The results generated were based on a ΔTmin of 10°C and pinch temperature of 46.3°C. Initial sensitivity analysis on the ΔTmin indicated that variation of total cost index is quite sensitive and increases with increase in ΔTmin at the temperature range of 14.5-30°C, however total cost index remains constant and minimal at a temperature range between 10°C-14.5°C for the CDU preheat train under study. In addition, the implementation of the optimum retrofit result is straightforward and feasible with minimum changes to the existing base case/design.

Membrane Distillation Desalination System With Gap Circulation and Cooling Using a Built-in Heat Exchanger

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Atia E. Khalifa
Keyword(s):  
Energy Consumption ◽  
Heat Exchanger ◽  
Specific Energy Consumption ◽  
Membrane Distillation ◽  
Operating Conditions ◽  
Water Desalination ◽  
Module Design ◽  
Membrane Surfaces ◽  
Best Value ◽  
Feed Temperature

Abstract A comprehensive experimental investigation is conducted to evaluate the performance of a new flux-enhanced compact water gap membrane distillation (WGMD) module design with gap circulation and cooling for water desalination. The new design uses a separate circulation loop to circulate the gap water, and a built-in heat exchanger coil implanted inside the coolant stream channel for cooling the circulated gap water. The WGMD modules with circulation and with circulation and cooling are compared with conventional WGMD without circulation. Variations of distillate flux, temperatures, and energy consumption are presented at different design operating conditions. Circulation and cooling of the gap water greatly enhance the output flux due to gap water motion and increase the temperature difference between membrane surfaces. However, the enhancement in flux was achieved at the expense of energy consumption. Circulation and cooling of gap water are more effective with bigger gap widths. Feed flowrate showed significant effects with gap water circulation and cooling. The electrical specific energy consumption (SEC) showed the best value of 7.9 and 8.8 kWh/m3 at a feed temperature of 70 °C for both conventional WGMD and WGMD with circulation modules, while the best value of SEC for the WGMD module with gap circulation and cooling was 9.4 kWh/m3 at a feed temperature of 80 °C.

Heat Exchanger Network Optimization by Differential Evolution Method

2014 ◽  
Vol 564 ◽  
pp. 292-297 ◽  
Author(s):  
Ngo Thi Phuong Thuy ◽  
Rajashekhar Pendyala ◽  
Nejat Rahmanian ◽  
Narahari Marneni
Keyword(s):  
Heat Exchanger ◽  
Differential Evolution ◽  
Network Optimization ◽  
Energy Utilization ◽  
Heat Exchanger Network ◽  
De Algorithm ◽  
Global Cost ◽  
Pinch Technology ◽  
Recent Developments

The synthesis of heat exchanger network (HEN) is a comprehensive approach to optimize energy utilization in process industry. Recent developments in HEN synthesis (HENS) present several heuristic methods, such as Simulated Annealing (SA), Genetic Algorithm (GA), and Differential Evolution (DE). In this work, DE method for synthesis and optimization of HEN has been presented. Using DE combined with the concept of super-targeting, the optimization is determined. Then DE algorithm is employed to optimize the global cost function including the constraints, such as heat balance, the temperatures of process streams. A case study has been optimized using DE, generated structure of HEN and compared with networks obtained by other methods such as pinch technology or mathematical programming. Through the result, the proposed method has been illustrated that DE is able to apply in HEN optimization, with 16.7% increase in capital cost and 56.4%, 18.9% decrease in energy, global costs respectively.

scholarly journals OPTIMAL DESIGN OF HEAT EXCHANGER NETWORK IN OIL REFINERIES

2021 ◽  
Vol 06 (02) ◽  
pp. 86-90
Author(s):  
Natig Abbasov Natig Abbasov ◽  
Ziyaddin Ziyaddinli Ziyaddin Ziyaddinli
Keyword(s):  
Heat Exchanger ◽  
Optimal Design ◽  
Catalytic Cracking ◽  
Essential Element ◽  
Practical Method ◽  
Fluid Catalytic Cracking ◽  
Oil Refinery ◽  
Heat Exchanger Network ◽  
Oil Refineries ◽  
Pinch Technology

The performance of the heat exchanger network (HEN) in a plant is an important aspect of energy conservation. “Pinch” technology and mathematical programming techniques offer an effective and practical method for designing the HEN for new and retrofit projects. The fluid catalytic cracking (FCC) is a dominant process in oil refineries and there has been a sustained effort to improve the efficiency and yield of the unit over the years. HEN optimal design in FCC process is an essential element in reducing the cost and improving the process as a whole. The objective of this work is to introduce a systematic procedure for designing optimal and flexible FCC-HEN that incorporates variations in feed flow rates and specs and on same time considers different schedules imposed on the process. Keywords: heat exchangers, fluid catalytic cracking, design of network, oil refinery, heat recovery systems

scholarly journals Energy and economy savings in the process of methanol synthesis unsig Pinch technology

2004 ◽  
Vol 69 (10) ◽  
pp. 827-837 ◽  
Author(s):  
Mirjana Kijevcanin ◽  
Bojan Djordjevic ◽  
Ozren Ocic ◽  
Mladen Crnomarkovic ◽  
Maja Maric ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Methanol Synthesis ◽  
Heat Exchangers ◽  
Energy Savings ◽  
Energy Costs ◽  
Pinch Analysis ◽  
Trade Off ◽  
Total Cost ◽  
Capital Costs ◽  
Pinch Technology

A heat exchanger network (HEN) for the process of methanol synthesis has been studied by pinch design analysis. Great economic and energy savings were realized by the pinch analysis in comparison to the existing plant. Also, it was found that it is possible to reduce the requirements for the consumption of utilities. The HEN was reconstruded by adding new heat exchangers. In order to produce new HEN, the capital costs had to be increased, but the total cost trade-off between the capital and energy costs will be decrease by 30 %.

Differences Between Second Law Analysis and Pinch Technology

1995 ◽  
Vol 117 (3) ◽  
pp. 186-191 ◽  
Author(s):  
D. A. Sama
Keyword(s):  
Heat Exchanger ◽  
Energy Recovery ◽  
Maximum Energy ◽  
Global Optimum ◽  
Second Law ◽  
Heat Exchanger Network ◽  
Second Law Analysis ◽  
Heat Exchanger Networks ◽  
Pinch Technology ◽  
Correct Design

The use of second law analysis to design a heat exchanger network is compared with the pinch technology approach. Differences between the two methods are identified and discussed in the light of claims made by practitioners of pinch technology. Second law insights are used to easily identify and correct design errors in a heat exchanger network, and to design maximum energy recovery networks. More importantly, it is found that use of the second law provides an understanding of the process which is totally absent in the pinch technology approach. The claims that pinch technology can find global optimum solutions, that only pinch technology can find maximum energy recovery heat exchanger networks, and that pinch technology is a form of second law analysis, are considered, discussed, and shown to be invalid.

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